1. Field of the Invention
The present invention is related to achieving video synchronization between a source end (i.e., a server end) and a destination end (i.e., a user end), and more particularly, to a method of identifying a target synchronization point pair corresponding to the source end and the destination end through a scan-line image matching scheme.
2. Description of the Prior Art
When watching pre-recorded TV programs, the user sometimes wants to view exciting events only. For example, when watching the pre-recorded baseball game, the user might have interest in those special moments when the home runs, hits, or strikeouts occur. To meet user's need, the source end (i.e., the server end), which is responsible for broadcasting a TV programs such as a sports game, is kind to distribute a highlight indexing file including time positions and time durations for the exciting events in the TV program. After the destination end (i.e., the user end) receives the highlight indexing file, it can uses the highlight indexing file to allow the user to quickly view any exciting events included in the recorded TV program.
However, a time shift may exist between the source end and the destination end due to discrepancy in time systems. For example, the source end has a universal time system, and the destination end has a time system asynchronous to the universal time system. As a result, the highlight location given under the universal time system at the source end might not work under a different time system at the destination end. Additionally, it is possible that the TV channel used at the source end for broadcasting the TV program is different from that used by the destination end for receiving the TV program. For example, the source end and the destination are located at different regions or countries. Therefore, the commercials inserted to the TV program broadcasted at the source end which provides the highlight indexing file might be different from that inserted to the TV program received at the source end. Furthermore, the video format of the TV program broadcasted at the source end might be different from that of the TV program received at the source end. For instance, the image resolution or frame rate (e.g., frame per second, FPS) varies due to different video settings at the source end and the destination end.
As a result, in order to quickly view exciting events by utilizing the highlight indexing file given by the source end, the user has to manually find the video synchronization point between the original TV program broadcasted at the source end and the received TV program recorded at the destination end. It is very inconvenient to the user at the destination end. Therefore, a robust, fast, and automatic synchronization algorithm is required to efficiently determine the time shift between the source end and the destination end.